Collapsible tire-band form



June 2, 1936. H. c. BOSTWICK 2,042,498

COLLAPSIBLE TIRE-BAND FORM Filed March 18, 1930 2 Sheets-Sheet 1 Fig.5 3mm C. Barlzuic/t June 2, 1936. H. c. BOSTWICK COLLAPSIBLE TIRE-BAND FORM Filed March 18, 1950 2 Shets-Sheet 2 Patented June 2, 1936 UNITED STATES COLLAPSIBLE TIRE-BAND FORM Henry C. Bostwick, Akron, Ohio, assignor to The Akron Standard Mold 00., Akron, Ohio, a corporation of Ohio Application March 18, 1930, Serial No. 436,716

56 Claims.

This invention relates to collapsible forms, sometimes known as chucks for building endless laminated bands and particularly semi-fiat bands for forming pneumatic tire casings.

Heretofore it has been necessary to stop the drum or core in order to collapse or expand it. One of the principal objects of my invention is to provide a drum or form which is automatic or semi-automatic in operation and adapted to be contracted and expanded while in rotation, thereby eifecting a saving of time and labor and also, if desired, bringing into play the action of centriiugal force as an aid in stripping the completed band from the drum.

A further object is to provide a collapsible form whose parts are at all times substantially in rotational balance, so that the structure may be rapidly rotated in either an expanded or collapsed condition without creating unbalanced centrifugal forces.

Further objects, are to provide a simple collapsible drum of decreased weight and cost as compared with prior ones, to obtain a greater contraction of the drum periphery than heretofore and otherwise to improve the construction and operation of apparatus of this class as will more fully hereinafter appear.

Of the accompanying drawings, Fig. 1 is a side elevation and partial axial section on the line l-I of Fig. 4 illustrating a preferred embodiment of my invention.

Fig. 2 is a partial longitudinal section thereof on the line 2-2 of Fig. 4.

Fig. 3 is a section on line 33 of Fig. 1.

Fig. 4 is a section on line 4-4 of Fig. 1.

Fig. 5 is a sectional view corresponding to Fig. 4 showing the drum in its collapsed condition.

In the drawings, Ill represents a portion of the casing of a tire-band building machine, from one side of which projects a horizontal drum shaft ll adapted to be rotated by power mechanism within the casing, inthe direction of the arrow A shown in Fig. 4, or counterclockwise as viewed from the front.

To the outer end of shaft ii is fixed, by means of a key I2 and set-screw B, the hub l4 of a two-armed spider I5 to whose ends are pivoted the four segments of a building form or drum l6 for making semi-flat tire bands. These segments are substantially equal in length and arranged in two pairs on opposite sides of the spider I5, the members ll, iii of each pair being hinged on the opposite arms of the spider upon pintles I 9 which are mounted in .earsjll, 2 i, respectively formed on which two segments are connected with the; splder arm on a single pivot axis.

Each drum segment could be of integral onepiece construction if intended for only one width of band, but where different widths are to be 5 made on the same machine, I prefer to provide a permanent inner or frame portion 22 upon which the hinge ears 2| are formed, and marginal shell members 23 telescopically fitted on said inner member and adjustably secured thereto by radial 19 cap-screws 24 on the shell members passing through transverse slots in member 22 for varying the effective width of thedrum, together with a thin circumferential bridge-plate 25 affixed to a central rib on said member 22 for bridging the spaces between said rib and the inner edges of the shell members 23 when the latter are extended. This axial adjusting means is covered in a divisional application Ser. No. 609,352, filed May 5, 1932. The drum edges are provided with the usual depressed bead seats 26, and the intermediate band-supporting portion may be flat as shown or otherwise shaped as desired.

21 is a sleeve structure surrounding the shaft l l and made in three parts, of which the forward member is a ring or collar 28 mounted to turn on the rear end of spider hub l4 and held against rearward axial movement thereon by 'a detachable retaining ring 29. The intermediate member of said sleeve structure includes a head 30 secured to collar 28 by means of bolts 3| and forwardly recessed to receive the retaining ring 29, and a tubular stem 32 integral with said head. The rear member of the sleeve structure is a brake wheel or drum 33 provided with a forwardly-projecting, tubular stem 34 which telescopes on the stem 32 and is adjustably fixed thereto bya bolt-and-slot connection 35 for the purpose of obtaining alignment of the drum with a stock rack or otherwise securing favorable working conditions by adjusting the alignment, without changing the location of the brake-drum. The structure including the collar 28, toggle links and tubular stem or shaft constitutes a collapsing mechanism for the drum.

It will be noted'in Figs. 4 and 5 that the duplicate drum segments I1 which are pivoted at opposite ends of a diameter of the spider l5, alternate with the similarly-pivoted duplicate segments l8, and the free end of each of the former .50 is connected by a short link 36, pivoted at 31 between ears 38 on the segment, with a forked arm 39 on the collar 28, by means of a pin 40, the link and collar arm forming a toggle which is nearly straightened in expanding the drum and is broken or folded in contracting it.

Each of the segments I8 is connected, from a pivot pin 4| carried by ears 42 projecting inwardly from said segment less than half-way forward-thereon from its pivot l9, through a longer 0 bent link 43 whose inner end occupies a recess in the collar 28, with a pivot pin 44 on said collar. Each of the segments I8 is further connected with the collar 28 by a helical pull-spring 45 conveniently attached at its outer end to the pivot pin M and at its inner end to a screw 48 on the collar. While these springs are not essential to the operation of the drum, they serve a useful purpose in taking up lost motion and holding the overlapping ends of the drum segments together when the drum is expanded.

The heels of adjacently-pivoted drum segments I], I8 are formed to abut in a radial joint 41 when the segments are expanded in a circle asindicated in Fig. 4, and the remote or free ends of adjoining segments overlap in a semi-tangent joint 48, the two joints 48 being slanted in the same sense or direction and each having an outwardly-exposed face 49 on the segment I! and an undercut face 50 on the segment I8. These slanting or overlapping ends are interlocked in the expanded condition by means of a tie-plate 5| affixed to the end of segment I! and having a dowel pin 52 adapted to enter a hole 53 in the end of the segment I8. The dowel and its hole are positioned in line with the path of movement of the segment ends as they come together, so that the interlocking connection will be automatically effected. There are preferably two of these tie plates 5|, placed adjacent the margins of the drum as seen in Fig. 2 foreach of the joints 48.

54 is a brake-band surrounding the drum 33, one end of said band being anchored to a fixed bracket 55 on the casing I0 and the other end connected with a pin 56 on the lower end of a hand lever 51 whichis pivoted at 58 on said casing', whereby the sleeve structure 21 and its collar 28 may be held or slowed down during the rotation of the drum shaft II while the drum I8 continues to revolve, for the purpose of collapsing the drum. The use of a mechanical brake isnot essential as the same effect can be obtained by manually arresting the drum 33, but I prefer to use the brake in order to save the operators hands.

For cushioning the radial arrest of the drum segments, especially at the end of their collapsing movement, I may interposed a dash-pot device between the spider I5 and a part connected with the collar 28 so as to control the movement of all four segments, such device as here shown including an air cylinder 59 pivoted to one of the arms of spider I5, and a piston, therein having its rod 8| pivotedon the linkpin 31 of the adjacent segment II. The weight of this cushioning means may be counterbalanced'by suitable masses on the opposite side of the shaft II, such as 62 and 63.

By a proper arrangement and proportioning of the parts, including the links 38 and 43 and their pivots, the inward movement of the free ends of the two segments I 1, when the drum is being collapsed, will precede that of the segments I8, so that each segment I8 will overlie the mating segment I1 in the collapsed condition as represented in Fig. 5. The weights of the several segments and their immediate connections-being approxi-' mately equal and symmetrically disposed as just described when the drum is collapsed, the drum may be rotated in its collapsed condition at any speed within the range of the machine without any substantial unbalanced centrifugal action and consequently without imposing harmful strains upon the shaft II or its bearings.

On the expanding movement, the toggle pin 44,

the shaft II and the drum I6 to be in rotation v in the direction of the arrow A (Fig. (l) or counterclockwise as viewed from the front, and assuming a tire band to have been formed on the drum, the operator collapses the drum by applying the brake band 54 to retard the rotation of the sleeve structure 21, including its collar 28, relative to that of the spider I5 and the drum segments. The initial forward displacement of the drum and spider with relation to collar 28 will slightly raise or move outwardly the free ends of the segments I8, and this initial movement, acting through the links 36 of the mating segments II, which links had not quite straightened out when the drum was expanded to its circular condition, will cause'the free ends of said' segments I I to be depressed or drawn inwardly, so that the interlocking dowels 52 on the plates 5| are quickly withdrawn from their holes 53. A continuation of the forward movement of spider I 5 relative to collar 28 brings the drum to the collapsed condition represented in Fig. 5, wherein its periphery is contracted well within the expanded diameter of the bead seats 26. To effect such degree of contraction it is desirable or necessary that some at least of the segments in their collapsed positions shall be eccentric to the axis of rotation of the drum, and in this embodiment all of the segments are so arranged. The brake can be applied to collapse the drum either while the power is on the shaft I I or when the power has been thrown off and the drum continues in rotation by its inertia or momentum. In either case, if the drum is revolving at substantial speed when the brake is applied, the action of centrifugal force upon the tire band aids in stripping it from the drum segments and allowing the latter to collapse inwardly. The collapsed drum having been brought to rest. the tire band is readily slipped off and the drum may then be automatically expanded by the action of centrifugal force upon the segments I1 and I8 when power is applied to the shaft II to rotate the latter while the brake is released. Be-

cause of the inherent decelerating action of the toggles, and especially the pairs formed by the collar 28 and links 43, as they approach or reach their straightened condition, the described connections perform the important function of arrestingthe centrifugal expanding movement of the drum segments substantially without shock, thereby practically eliminating the tendency to- .ward breakage of parts under those conditions. In the collapsed condition of the drum, the tension of the springs 45 is exerted in a direction tending to straighten the toggles and hence to expand the drum, but their strength is insufflcient to overcome the friction of the parts.

From the foregoing, it will be evident that my invention provides a simple, light-weight, inexpensive, segmental band form adapted particu larly for making semi-fiat tire bands and capaable of being collapsed and expanded while the form is in rotation, threby reducing the time required for these operations and also saving the strength of the operator as compared with prior practice. The present invention, so far as I am aware, is the first in this art to perform the function of collapse and expansion of a segmental drum while in rotation.

My invention is not wholly confined to forms for making flat or semi-flat bands, and various changes of embodiment are contemplated as coming within the scope of the claims, such as the provision of any other progressively acting device equivalent to the brake 33, 54 for collapsing the drum substantially in the manner described. I claim:

1. A rotary segmental form expansible by centrifugal force, toggle means movable to and past a fully straightened position by the expansion to render it substantially without shock, and relatively rotatable means for collapsing said form;

for effecting the collapse of said segments while the drum is in rotation.

4. The combination of a collapsible rotary form having collapsing mechanism, means for rotating the same, and progressively acting means independent of said form-rotating means, engageable with said collapsing mechanism during rotation of the form and controllable by the 49 operator for applying the momentum of said form to collapse the latter during continued rotation thereof.

- 5. In a tie-band building machine, the combination of a power shaft, a segmental drum device thereon expansible by centrifugal force and inherently maintained in-its expanded condition, and brake-actuated retarding means operable at will and connected with-the'drum segments for collapsing the latter by their power of rotation.

6. A drum having depressed bead seats and collapsible to a circumference less than that ofv said seats for building a semi-flat tire band,

means for rotating said drum, and means for applying its power of rotation to collapse the drum during continued rotation thereof while centrifugal force acting on the formed band aids in causing it to be-stripped from the drum surface.

'7. A rotary tire form comprising a spider having at each end a pair of parallel,angularly spaced pivot pins, and two pairs of form segments whose members are pivoted on the respective pins N 8. A collapsible tire-band form comprising a rotary support, a drum thereon composed of a series of adjacent segments interconnected for concurrent inward movement and including a 1.

segment movable to a collapsed position eccentric to the drum axis, and manually-controllable ments for applying the power of rotation of said drum to collapsethe latter.

9. A band-forming drum comprising a rotary" brakingv means affecting the entire series of seament, a brake-controlled retardable rotary collar, and means connecting said collar with the segments for collapsing. all of ,the latter by their power of rotation.

10. A segmental rotary drum, a driving shaf 5 carryingsaid drum, rotary means surrounding and rotatable about the shaft and retardable to collapse said drum, and a brake operable at will for retarding said means.

11. A collapsing band-building form compris- 10 ing a rotary support, a pair of form segments pivoted thereto, a coaxial relatively-rotatable operating device, and relatively long and short links connecting said device with the respective members of said pair of segments. 10

12. In a collapsible band-building form, the combination of a pair of pivoted form segments whose ends abut in a semi-tangent joint when the form is expanded, and controlling means for the overlapping segment adapted to swing said 20 segment outwardly beyond its ultimate position and then inwardly against the mating segment end when said segments are moved to their operative position.

13. A collapsible band-building form comprising a rotary support, a pair of 'formsegments pivoted thereto, one of which overlaps the other,

a relatively-retardable collar, a relatively-short link connecting said collar with the underlapping segment and movable short of its straightened condition to carry said segmentinto operative position, and a relatively-long link connecting said collar with the overlapping segment and movable to a straightened condition and beyond, to carry said segment outwardly beyond its ultimate position and then inwardly into operative relation, to theun'derlapping segment.

14. A collapsible form expansible by centrifugal force and comprising interconnected segments one of which is movable outwardly beyond 40 its operative position and movable inwardly to said position by centrifugal force acting on another of the segments. r

15. A collapsible drum including a pair of coacting pivotedsegments, means for automatically interlocking their ends, collapsing means for separating said ends by an initial outward radial movement of one and inward radial movement of the other, and a spring for holding said ends together in expanded condition.

16. A rotary drunr shaft having a drum support, a collapsible, segmental drum mounted on said support,.means supported by and surrounding said shaft at the rear of said drum support for controlling the collapse of the drum, and means for fixing the drum on the shaft in varying axial relation to said controlling means.

1'7. The combination of a rotary segmental drum, coaxial means including telescoped members for controlling the collapse of said drum, and means for fixing said members together at different axial adjustments.

18. A collapsible drum composed of adjacent, coacting, pivot d segments collectively expansible by centrifugal force, and a toggle controlling the motion of said adjacent segments.

i 19. A collapsible drum having two adjacent, coacting, pivoted segments collectively expan sible by centrifugal force, a rotary shaft carrying said drum, and two toggles including a 70 common ring surrounding and turnable on said shaft, for controlling the respective segments, one of said'toggles being carried short of and the other beyond its straightened condition as the'drum is expanded to its final shape.

iii

20. A tire supporting chuck comprising a plurality of arcuate segments having bead seats and collectively collapsible to a circumference less than that of said seats, a shaft, arms on the shaft, means pivotally connecting an end of each segment to one of the arms, and additional means including a braking device for controlling the free ends of the segments.

21. A tire supporting chuck comprising a plurality of pairs of arcuate segments, a shaft, arms secured to the shaft, each pair of segments having their adjacent ends pivotally connected to one of the arms, and a braking device for controlling movement of the free ends of the segments. v

22. A tire supporting chuck comprising a shaft, a plurality of arcuate segments collectively forming an entire drum periphery, arms secured to the shaft, means pivotally connecting each of the segments to the arms, and a braking device for controlling the movement of certain of the segments.

23. A tire supporting chuck comprising a driven supporting member, arms secured to such member, a plurality of arcuate segments adapted to form a substantially circular drum, means pivotally connecting an end of each segment to one of the arms, a double toggle linkage interconnecting certain segments, and means including a brake drum and a brake band for controlling movement of certain of the segments.

24. A tire supporting chuck comprising a shaft, a plurality of arcuate segments, an arm, means pivotally connecting an end of each segment to the arm, and means including a sleeve and a braking device engageablewith the sleeve for controlling the movement of the free ends of the segments.

25. Band-building apparatus for inextensiblebead tire casings comprising a rotary segmental form having depressed bead seats and collapsible within the diameter of said seats by power furnished by rotation thereof, and manually-operable brake means associated with said form for bringing said power into action.

26. A rotary band-building form having its entire periphery composed of four segments movable inwardly to positions eccentric to the form axis to collapse the form, brake-controlled rotary retardable operating means, and connections from said means to the form segments for collapsing the latter when said means is retarded.

27. A tire supporting chuck comprising a,

driven supporting member, arms secured to such member, a plurality of arcuate segments adapted to form a substantially circular drum, means pivotally connecting an end of each segment to one of the arms, shorter arms rotatably mounted on the supporting member, links pivotally connecting the free ends of the shorter arms to the free ends of certain of the segments, and a braking device for .arresting movement of the shorter arms.

28. Band building apparatus comprising a drum structure adapted for building and rolling down tire bands and including segments pivotally mounted to expand and collapse said structure, a power shaft supporting said structure, a sleeve around said shaft, rotatable with or relative to the shaft and having connections with certain of the segments for moving the same from a fully expanded to a fully collapsed position in less than one rotation of said sleeve around the shaft, and a friction brake operable at will for retarding said sleeve during forward rotation, to collapse the segments.

29. A collapsible drum structure comprising a central rotary power shaft, a spider thereon, two pairs of segments pivotally supported by said spider in couples on opposite sides of the shaft and meetingin overlapping end-to-end relation, a sleeve surrounding and rotatable with and relative to said shaft rearwardly of the spider and having its forward end located within the drum and linked to opposite segments for collapsing the same when said sleeve is retarded with respect to the shaft, a brake drum on the rear portion of said sleeve, and a brake coacting with said brake drum to arrest the sleeve.

30. Band-building apparatus comprising a collapsible drum composed of overlapping and underlapping segments meeting in end-to-end relation, a segment support, a controlling member rotatable with and relative to said support and having connections with the underlapping segments for initiating their collapsing movement in advance of that of the overlapping segments, and additional connections actuated by relative rotation of said controlling member for thereafter moving inwardly the free ends of the overlapping segments.

31. A collapsible tire-building chuck comprising a central rotary power shaft, a spider thereon, two pairs of drum segments movably supported by said spider in couples on opposite sides of the shaft and including members having their free ends in overlapping and underlapping relation, the underlapping segments being pivotally mounted, and relatively rotatable sleeve surrounding said shaft and having toggle link connections with the underlapping segments for inwardly moving their free ends in advance of those of the overlapping segments when the sleeve is relatively rotated, and means operated by relative rotation of said sleeve for thereafter moving inwardly the free ends of the overlapping segments.

32. A collapsible band-building chuck comprising a central rotary driving shaft, a drum car-' ried thereby and composed of segments movable to collapsed positions in which they are collectively in substantial rotational balance, said drum including pivotally supported segments meeting in end-to-end relation when expanded, and lying one over the other when collapsed, a controlling member coaxial with said shaft and rotatable with or relative thereto, and'segment operating connections, including toggle links actuated by the controlling member and foldable therewith circumferentially of said shaft, for fully collapsing all of the drum segments in less than one relative rotation of said shaft and member, said connections producing a greater pivotal collapsing movement of the underlying than of the overlying segments.

33. A collapsible tire-building chuck comprising a drum having depressed bead seats and composed of two pairs of pivoted segments with complemental beveled' free ends which, when the drum is expanded, meet in overlapping and underlapping relation, said segments being mounted in couples whose members swing oppositely to an overlying and underlying relation with those of the other couple, a central rotary power shaft extending axially into the middle region of said drum and having a spider supporting the respective segment couples, a sleeve surrounding and rotatable about said shaft, and

sleeve-actuated connections for positively collapsing all of the drum segments in less than one relative rotation of the sleeve on the shaft, said connections being adapted to deregister the meeting ends of the segments before the overlapping segments move inwardly.

34. The combination of a collapsible, rotary, tire-building form having collapsing mechanism for stripping the form from the inner surfaces of a tire built thereon, means for rotating the same, and progressively acting means independent of said form rotating means engageable with said collapsing mechanism during rotation of the form and controllable by the operator for applying the momentum of said form to collapse the latter during continued rotation thereof whereby a tire may be removed therefrom.

35. A tire building form including a plurality of sections collapsible to strip the form from inner surfaces of a tire built thereon to permit removal of a tire from the form after it has been built thereon, means for supporting and rotating said form including rotatable members adapted to rotate in unison or relative to each other and to support the form in expanded position, both in a state of rest and while rotating, connections between said members and the form for collapsing the form whereby a tire may be removed therefrom and also for expanding the form after removal of the tire upon relative rotation of said members, and power means for rotating said members in unison and also for causing relative rotation thereof when rotation of .one of said members is hindered, whereby said form may be socollapsed or expanded by power by a single operation of said power means to relatively rotate said members.

36. A tire building form including a plurality of collapsible sections, means for supporting and rotating saidform including rotatable members adapted to rotate either in unison or relatively and to support the form in expanded condition in a state of rest as well as in motion, connections between said members and said form for collapsing the same upon relative rotation of said members to strip the form from inner surfaces of a tire built thereon, and power means for rotating said members in unison and also operable to cause relative rotation of said members upon hindering rotationof one of said members, whereby said form is so collapsed by power by a single operation of said power means relatively to rotate said members 37. The combination in a tire building form of relatively rotatable members for operating a plurality of form sections constituting the entire form to collapse the entire form whereby the form is stripped from inner surfaces of a tire built thereon, one of said members comprising a power-operated shaft, and one of said members 'being adapted to be held against rotation with 38. A tire building form including a plurality of collapsible sections, means for supporting and rotating said form including rotatable members adapted to rotate either in unison or relatively and to support the form in expanded condition in a state of rest as well as in motion, connections between said members and saidv form for collapsing all of the collapsible sections of the form upon relative rotation of said members to strip the form from inner surfaces of a tire built thereon, and power means for rotating said members in unison and also operable to cause relative rotation of said members upon hindering rotation of 5 one of said members, whereby said form is so collapsed by power by a single operation of said power means relatively to rotate said members.

39. A tire-band building form composed of sections relatively movable to collapse the form, a rotary support for said sections, retardable means movable on said support and having connections controlling the relative movement of said sections for completely collapsing the form by its own momentum when rotating in a forward direction, and a friction brake operable on said retardable means for efl'ecting such collapse.

40. A tire-band building form having a plurality of sections movable to collapse the form, relatively retardable means having connections operating on all of the movable sections and adapted to completely collapse the form by its own momentum in less than one rotation thereof in a forward direction, and a friction brake operable on said retarding means for effecting such col- 25 lapse.

41, A rotary tire-band building drum composed of overlapping and underlapping segments radially movable inwardly to collapse the drum, a retardable member having connections for unequally collapsing the underlapping and overlapping segments in timed relation while the drum is forwardly rotating, and brake means controlling said retardable member for effecting collapse of the drum by its own momentum. 3

p 42. A rotary collapsible band-builder comprising. a central segment carrier, a building form havingits entire periphery composed of four movable segments supported by said carrier and including a pair of opposite pivotally mounted seg- 40 ments, controlling means within the drum, concentric with and rotatable relative to said carrier and having an external wheel with its periphery exposed for engagement to produce the relative rotation of said means at will, and operating con- 45 nections actuatedby said controlling means for drawing inwardly all of said segments into underlying and overlying collapsed relation.

43. Arotary collapsible band-builder comprising a central segment carrier, a building form so having its entire periphery composed of four pivoted segments supported by said carrier in couples at opposite sides of the form, the end of one member of each couple overlapping that of the other member of the opposite couple, and con- 55 trolling means concentric with the axis of rotation ,of the form and rotatable relative to said carrier and having connections for producing the complete collapse of all of said segments,

and moving the underlapping segments inwardly in advance of the overlapping ones.

44. A rotary collapsible band-builder comprising a drum having its entire periphery composed of four segments, a central carrier pivotally supporting said segments in two opposite couples, 05 the members of each of which swing oppositely into underlying and overlying collapsed relation. to those of the other couple, a control sleeve concentric withand rotatable relative to said carrier, toggle links connecting said sleeve with the underlying segments for-moving the latter, and additional connections actuated by said sleev for moving the overlying segments.

45. A band builder according to claim 44 in which the additional connections are bent links connecting said sleeve with the overlying segments.

46. Building apparatus for inextensible-bead pneumatic tire bands comprising a rotary drum composed entirely of pivoted segments having depressed bead seats, a carrier pivotally supporting the segments and having fixed pivots for a pair of segments on opposite sides of the drum, and operating means for all of the segments adapted to collapse the drum in its own plane to a minor diameter at the median plane less than the mean expanded diameter of said bead seats.

47. A rotary collapsible builder for inextensihie-bead tire bands comprising a segment carrier, a drum composed of segments having depressed marginal bead seats and pivotally supported by said carrier in opposite couples, each comprising oppositely swinging members which meet those of the other couple in underlapping and overlapping end-to-end relation, and operating devices within the drum including a controlling member concentric with the axis of rotation of the drum and rotatable relative to said carrier and connections actuated by said member for operating all of said segments to collapse the drum to a size permitting removal of the depressed-bead band.

48. A rotary collapsible builder for inextensible-bead tire bands comprising a segment carrier, a drum composed of four segments having depressed marginal bead seats and pivotally supported by said carrier ineopposite couples, each comprising oppositely swinging members with beveled ends meeting those of the other couple in underlapping and overlapping relation, and operating devices within the drum including a controlling member concentric with the axis of rotation of the drum, rotatable with and relative to said carrier, and connections between said member and all four segments for completely collapsing said segments in less than one relative rotation of said member, to a size permitting removal of the depressed-bead band.

49. A rotary collapsible builder for inextensible-bead tire bands comprising a segment carrier, a building drum composed of pivotallymounted segments supported by said carrier and having depressed bead seats, the meeting free ends of said segments being in underlapping and overlapping relation, a controlling member rotatable with and relative to said carrier, concentric with the latters axis of rotation, and connections operated by said controlling member for separately actuating said underlapping and overlapping segments to collapse them in timed relation avoiding interference between said free ends, to a drum size permitting removal of the depressed-bead band.

' 50. A rotary collapsible tire-builder comprising a segment support, a concentric controlling mem ber rotatable with and relative thereto, a pair of underlapping and a pair of overlapping segments pivotally carried by said support in opposite couples, toggle links connecting said controlling member with the underlapping segments and foldable with said member circumferentially of the drum for initiating the inward movement of the free ends of said underlapping segments at a time when those of the overlapping segments have no inward movement, and additional operating connections for the overlapping segments, operated by relative rotation of said membuilding drum composed of segments pivotally carried by said support by means including fixed pivots at opposite sides of the form, and circum-' ferentially foldable operating connections for collapsing all of the segments by relative rotation of said member, adapted to maintain said drum in expanded condition, against starting inertia, for band-building operations in either 3 direction of drum rotation.

53. A collapsible band-builder comprising a rotary segment support, a controlling member rotatable with and relative thereto, concentric with the axis of rotation of said support, a building drum composed of two pairs of underlapping and overlapping segments pivotally carried by said support in opposite couples, and operating means including circumferentially foldable toggle-link connections from said member to the underlapping segments and additional connections operated by said member for actuating the overlapping segments, to collapse the drum, said connections collectively being adapted to maintain the drum expanded for band-building operations in both directions of drum rotation.

- 54. A rotary collapsible tire-band builder comprising a segment support, a relatively rotatable concentric controlling member, a band-building drum composed of underlapping and overlapping segments movably carried by said support, and operating connections actuated by said member for moving said overlapping segments outwardly beyond their ultimate position and then inwardly against the mating underlapping segments to maintain the drum, by the binding action of the band thereon during reverse rotation, in an expanded condition for band-building operations in both directions of drum rotation.

55. A rotary tire-building form having its periphery composed of segments arranged in opposite couples each including an overlapping and an underlapping segment at least one of which is mounted on a radially-fixed pivotal axis and whose end abuts that of the adjacent segment of the other couple in the expanded condition, said segments being inwardly movable to collapse the torm and outwardly movable by centrifugal force when the form is rotated to automatically expand it, and means for operating and controlling all of the segments, including toggle devices constituting, together with said abutting of adjacent segment ends, the sole means for arresting the-outward movement of said segments, and movable to a fully straightened arresting position by said movement.

56. A form according to claim 55 having its masses disposed substantially in rotational balance in both the expanded and the collapsed condition and having all segments pivotally mounted and at all times symmetrically disposed about the center of rotation of the form.

HENRY C. BOS'I'WICK. 

